Requests From the Server to Itself

When the Apache HTTP Server manages its child processes, it needs a way to wake up processes that are listening for new connections. To do this, it sends a simple HTTP request back to itself. This request will appear in the access_log file with the remote address set to the loop-back interface (typically 127.0.0.1 or ::1 if IPv6 is configured). If you log the User-Agent string (as in the combined log format), you will see the server signature followed by "(internal dummy connection)" on non-SSL servers. During certain periods you may see up to one such request for each httpd child process.

These requests are perfectly normal and you do not, in general, need to worry about them. They can simply be ignored.

If you wish to exclude them from your log, you can use normal conditional-logging techniques. For example, to omit all requests from the loopback interface from your logs, you can use

SetEnvIf Remote_Addr "127\.0\.0\.1" loopback

and then add env=!loopback to the end of your CustomLog directive.

In 2.2.6 and earlier, in certain configurations, these requests may hit a heavy-weight dynamic web page and cause unnecessary load on the server. You can avoid this by using mod_rewrite to respond with a redirect when accessed with that specific User-Agent or IP address.

SSL Considerations

The internal dummy connections are not capable of speaking SSL. Thus, on servers with SSL enabled, these requests may generate noise in the server error log similar to the following:

Monday, June 22, 2015

We get this error when re-trying to install magento. This happens because magento stores the log of the previous installation date and before carrying out installation process again it checks for previous installations and it does so by checking the date which is stored inside the xml file.

Wednesday, June 10, 2015

If your Single Page Application is slow or have large DOMs, removing a previously-attached event handler from the elements may help to prevent it being bound twice or few times.

.off( events [, selector ] [, handler ] )

Remove an event handler.

.empty()

Remove all child nodes of the set of matched elements from the DOM.

.remove( [selector ] )

Remove the set of matched elements from the DOM.

Similar to .empty(), the .remove() method takes elements out of the DOM. Use .remove() when you want to remove the element itself, as well as everything inside it. In addition to the elements themselves, all bound events and jQuery data associated with the elements are removed. To remove the elements without removing data and events, use .detach() instead.

.detach( [selector ] )

Remove the set of matched elements from the DOM.

Looping through the direct children:

$("#div1").children().off();
$("#div1").children().empty();

or

$("#div1").children().remove();

Looping through all descendants:

$("#div1").find('*').off();
$("#div1").find('*').empty();

or

$("#div1").remove();

this example .off() is called immediately to ensure previous events (of any kind) with the namespace are un-bound:

Ok so I have reworked my code so that when a tab is closed, all widgets are destroyed, all handlers created by .on() are removed with .off() and the containing DIV is emptied with .empty(). This has DRAMATICALLY improved the performance alone.

Note: similar to .empty(), the .remove() method takes elements out of the DOM. Use .remove() when you want to remove the element itself, as well as everything inside it. In addition to the elements themselves, all bound events and jQuery data associated with the elements are removed. To remove the elements without removing data and events, use .detach() instead.